Also, you may be able to use pictures as well. Like:
Show Pic: 1 [Hero Upper Body]
Move Pic: (From left to right)
Text: Blah blah blah.
So you'd have the pic of the hero slide in from off screen to the left lower corner of the screen. And no, I do not imply that it would be over top of the text message, it's so that if you have a full body image of the hero, you can slide it in and the Head and shoulders would be above the text, while the rest of the body would be hidden or slightly transparent behind the text message. Then to get rid of him, you can slide him off and then erase it, or if you want like another character to start talking, you can leave the hero image up there and then slide in the other character that's talking from off screen to the right side of the message, etc.
However, if you want something fancy like the face IN the message, then do as Zylos said and look for those scripts.